Method and apparatus for detecting embedded rebar within an interaction region of a structure irradiated with laser light

ABSTRACT

A detection system is used during irradiation of an interaction region of a structure with laser light. The structure includes embedded material. The detection system includes a focusing lens positioned to receive light emitted from the interaction region. The detection system further includes an optical fiber optically coupled to the focusing lens to receive light from the focusing lens. The detection system further includes a spectrometer optically coupled to the optical fiber to receive light from the optical fiber. The spectrometer is adapted for analysis of the light for indications of the embedded material within the interaction region.

RELATED APPLICATIONS

[0001] This application claims benefit under 35 U.S.C. § 119(e) to U.S.Provisional Patent Application No. 60/456,043, filed Mar. 18, 2003, toU.S. Provisional Patent Application No. 60/471,057, filed May 16, 2003,and to U.S. Provisional Patent Application No. 60/496,460, filed Aug.20, 2003, each of which is incorporated in its entirety by referenceherein. This application is related to U.S. Patent Application Nos.______(Attorney Docket No. LOMASR.021A),______ (Attorney Docket No.LOMASR.023A),______ (Attorney Docket No. LOMASR.024A), ______(AttorneyDocket No. LOMASR.025A), each of which is filed on even date herewithand incorporated in its entirety by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT

[0002] This invention was funded, in part, by the Federal EmergencyManagement Agency as part of the Robert T. Stafford Disaster Relief andEmergency Assistance Act (42 U.S.C. § 5121 et seq.).

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to the field of materialprocessing, particularly, to an apparatus and method for drilling,cutting, and surface processing of materials using energy waves.

[0005] 2. Description of the Related Art

[0006] Those in the wide ranging materials processing industries havelong recognized the need for non-disruptive material processing. In thepast, virtually all material processing, including drilling, cutting,scabbling, and the like have included numerous disruptive aspects (e.g.,noise, vibration, dust, vapors, and fumes). Material processinggenerally includes mechanical technologies such as drilling, hammering,and other power assisted methods, and water jet based technologies.Demonstrative of the problems of material processing, U.S. Pat. No.5,085,026 is highly illustrative. The '026 device requires mechanicaldrilling of materials such as concrete or other masonry, and generatesall the disruptive aspects noted above.

SUMMARY OF THE INVENTION

[0007] In certain embodiments, a detection system is used duringirradiation of an interaction region of a structure with laser light.The structure comprises embedded material. The detection systemcomprises a focusing lens positioned to receive light emitted from theinteraction region. The detection system further comprises an opticalfiber optically coupled to the focusing lens to receive light from thefocusing lens. The detection system further comprises a spectrometeroptically coupled to the optical fiber to receive light from the opticalfiber. The spectrometer is adapted for analysis of the light forindications of the embedded material within the interaction region.

[0008] In certain embodiments, a detection system is used duringirradiation of an interaction region of a structure with laser light.The structure comprises embedded material. The detection systemcomprises means for focusing light emitted from the interaction region.The detection system further comprises means for separating the focussedlight into a spectrum of wavelengths. The detection system furthercomprises means for analyzing at least a portion of the spectrum forindications of embedded material within the interaction region.

[0009] In certain embodiments, a method detects rebar within alaser-irradiated interaction region of a structure comprising embeddedmaterial. The method comprises focussing light from the interactionregion. The method further comprises separating the light into aspectrum of wavelengths. The method further comprises analyzing at leasta portion of the spectrum for indications of embedded material withinthe interaction region.

[0010] For purposes of summarizing the present invention, certainaspects, advantages and novel features of the present invention havebeen described herein above. It is to be understood, however, that notnecessarily all such advantages may be achieved in accordance with anyparticular embodiment of the present invention. Thus, the presentinvention may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Without limiting the scope of the present invention as claimedbelow and referring now to the drawings and figures:

[0012]FIG. 1 schematically illustrates an embodiment of an apparatus forprocessing a surface of a structure;

[0013]FIG. 2 schematically illustrates a laser base unit compatible withembodiments described herein;

[0014]FIG. 3A schematically illustrates a laser head in accordance withembodiments described herein;

[0015]FIGS. 3B and 3C schematically illustrate two alternativeembodiments of the laser head;

[0016]FIG. 4 schematically illustrates a cross-sectional view of acontainment plenum in accordance with embodiments described herein;

[0017]FIG. 5 schematically illustrates a laser head comprising a sensoradapted to measure the relative distance between the laser head and theinteraction region;

[0018]FIGS. 6A and 6B schematically illustrate two opposite elevatedperspectives of an embodiment in which the laser manipulation systemcomprises an anchoring mechanism adapted to be releasably coupled to thestructure and a positioning mechanism coupled to the anchoring mechanismand coupled to the laser head;

[0019]FIG. 7 schematically illustrates an embodiment of an attachmentinterface of the anchoring mechanism;

[0020]FIG. 8 schematically illustrates an exploded view of oneembodiment of the positioning mechanism along with the attachmentinterfaces of the anchoring mechanism;

[0021]FIG. 9 schematically illustrates an embodiment of a first-axisposition system;

[0022]FIG. 10 schematically illustrates an embodiment of a second-axisposition system;

[0023]FIGS. 11A and 11B schematically illustrate an embodiment of aninterface in two alternative configurations;

[0024]FIG. 12 schematically illustrates an embodiment of a laser headreceiver;

[0025]FIG. 13 schematically illustrates an embodiment of a supportstructure coupled to the other components of the apparatus;

[0026]FIG. 14A schematically illustrates an embodiment of asuspension-based support system coupled to the apparatus;

[0027]FIG. 14B schematically illustrates an embodiment of the apparatuscomprising suspension-based support connectors;

[0028]FIG. 15 schematically illustrates an embodiment of a controllercomprising a control panel, a microprocessor, a laser generatorinterface, a positioning system interface, a sensor interface, and auser interface;

[0029]FIG. 16 schematically illustrates a control pendant comprising ascreen and a plurality of buttons;

[0030]FIG. 17A illustrates an exemplary “MAIN SCREEN” display of thecontrol pendant;

[0031]FIG. 17B illustrates an exemplary “SELECT OPERATION SCREEN”display of the control pendant;

[0032]FIG. 17C illustrates an exemplary “CIRCLE SETUP/OPERATION SCREEN”display of the control pendant;

[0033]FIG. 17D illustrates an exemplary “PIERCE SETUP/OPERATION SCREEN”display of the control pendant;

[0034]FIG. 17E illustrates an exemplary “CUT SETUP/OPERATION SCREEN”display of the control pendant;

[0035]FIG. 17F illustrates an exemplary “SURFACE KEYING SETUP/OPERATIONSCREEN” display of the control pendant;

[0036]FIG. 17G illustrates an exemplary “FAULT SCREEN” display of thecontrol pendant;

[0037]FIG. 17H illustrates an exemplary “MAINTENANCE SCREEN” display ofthe control pendant;

[0038]FIG. 18 schematically illustrates a detector compatible withembodiments described herein; and

[0039]FIG. 19 shows a graph of the light spectrum of wavelengthsdetected upon irradiating concrete with laser light and the lightspectrum detected upon irradiating concrete with embedded rebar.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0040] Reducing the disruptive aspects of material processing has longbeen a goal of those in materials processing industries, particularly inindustries that require materials processing within or near occupiedstructures, such as is common in renovation and many other applications.Such long-felt needs have been particularly prevalent in seismicallyactive areas of the earth, where there is a pressing need for aneffective and economical means of retrofitting occupied structures toincrease the safety of these structures.

[0041] Prior technologies are plagued by disruptive characteristics,thereby making them virtually unsuitable for retrofitting occupiedstructures. Additionally, such material processing technologies oftenpresent dangerous and costly “cut through” dangers. “Cut through”dangers include instances such as a worker unintentionally cutting anembedded object while drilling through the subject material. Forexample, a construction worker drilling a hole in an existing concretewall may accidentally encounter reinforcing steel or rebar, or embeddedutilities, such as live electrical conduit and conductors. Such anincident may result in costly damage to tools or the subject material,as well as potentially deadly consequences (e.g., electrocution) forworkers. Traditional drilling methods also can include “punch through”dangers of unexpectedly punching through the material drilled anddamaging structures or personnel on the opposite side of the material.

[0042] In addition, traditional material processing equipment has beenextremely burdensome to operate. Handheld power drilling and hammeringdevices commonly weigh in excess of fifty pounds and are often requiredto be held overhead by the operator for extended period of time.Conventional devices also typically produce jarring forces that theoperator must absorb while holding the device. Besides the potentiallyinjurious jarring forces, sustained heavy lifting, and “cut through”dangers, the operator and those in the vicinity of the device may beexposed to falling or projectile debris, as well as dust, fumes, vapors,vibration, and noise. This level of noisome activity is unsuitable ingeneral for occupied structures, and is entirely unsuitable forstructures used as hospitals, laboratories, and the like, where noiseand vibration can be completely unacceptable.

[0043] What continues to be needed but missing from this field of art isa non-disruptive material processing technology that overcomes thedrawbacks illustrated above. In certain embodiments described herein,energy waves are directed toward the surface to be processed to overcomesome or all of such drawbacks. The energy waves of certain embodimentsare electromagnetic waves (e.g., laser light, microwaves), while inother embodiments, they are acoustic waves (e.g., ultrasonic waves).However, in certain embodiments, such cutting units can be as bulky andoften are as difficult to maneuver as their mechanical counterparts. Inaddition, lasers can be subject to the same “cut through” dangers asdescribed above, wherein objects hidden within the matrix of thematerial to be processed can be inadvertently damaged. Lasers can alsopose additional dangers of “punch through” with danger to persons orobjects in the path of the laser beam. Lasers can also presentcomplexities in removing drilled material from a cut or a drilled hole.In certain embodiments, the laser system would incorporate a remotelaser generator communicating with a portable processing head thatincorporates numerous non-disruptive and safety features allowing thesystem to be utilized within or near occupied structures.

[0044] Certain embodiments of the present invention provide fastmaterial processing while addressing many of the shortcomings of priortechnologies and allowing for heretofore unavailable benefits (e.g.,reduced disruption to activities within the structure). In certainembodiments, the method and apparatus utilize fiber connections betweenelements such that noisy, bulky, and heavy elements can operate at asignificant distance from the actual work area. Certain embodiments arelow in both noise and vibration during operation, and effectively removedust and debris. Certain embodiments include a detection system toreduce the dangers of “cut through” or “punch through.” Certainembodiments enhance worker safety by allowing workers to be located awayfrom the work area during material processing. Certain embodiments areseparable into man-portable pieces (e.g., less than 50 pounds) tofacilitate transportation to locations in proximity to or within thestructure being processed by providing easy and fast portability andset-up.

[0045] Certain embodiments of the present invention provide a method andapparatus for processing fragile structures which may be damaged byconventional processing techniques. For example, using conventional sawsfor processing concrete grain silos as part of a retrofit orrefurbishment process may result in vibrations damaging to otherportions of the silo. Using a laser to process the fragile structure canreduce the collateral damage done to the structure during processing.Furthermore, certain embodiments described herein are easilyassembled/disassembled, so they can be used in otherwise inaccessibleportions of the structures. While embodiments described herein aredisclosed in terms of processing man-made structures, in still otherembodiments, the present invention can be useful for processing naturalformations (e.g., as part of a mining or drilling operation).

[0046] The method and apparatus described herein represent a significantadvance in the state of the art. Various embodiments of the apparatuscomprise new and novel arrangements of elements and methods that areconfigured in unique and novel ways and which demonstrate previouslyunavailable but desirable capabilities. In particular, certainembodiments of the present invention provide a material processingmethod that is quiet, substantially vibration-free, and less likely toexude dust, debris, or noxious fumes. Additionally, certain embodimentsallow a higher rate of material processing than do conventionaltechnologies.

[0047] The detailed description set forth below in connection with thedrawings is intended merely as a description of various embodiments ofthe present invention, and is not intended to represent the only form inwhich the present invention may be constructed or utilized. Thedescription sets forth illustrated embodiments of the designs,functions, apparatus, and methods of implementing the invention. It isto be understood, however, that the same or equivalent functions andfeatures may be accomplished by different embodiments that are alsointended to be encompassed within the spirit and scope of the invention.

[0048]FIG. 1 schematically illustrates an embodiment of an apparatus 50for processing a structure having a surface. The apparatus 50 comprisesa laser base unit 300, a laser manipulation system 100, and a controller500. The laser base unit 300 is adapted to provide laser light to aninteraction region and includes a laser generator 310 and a laser head200 coupled to the laser generator 310. The laser head 200 is adapted toremove the material from the interaction region. The laser manipulationsystem 100 includes an anchoring mechanism 110 adapted to be releasablycoupled to the structure and a positioning mechanism 121 coupled to theanchoring mechanism 110 and coupled to the laser head 200. The lasermanipulation system 100 is adapted to controllably adjust the positionof the laser head 200 relative to the structure. The controller 500 iselectrically coupled to the laser base unit 300 and the lasermanipulation system 100. The controller 500 is adapted to transmitcontrol signals to the laser base unit 300 and to the laser manipulationsystem 100 in response to user input.

[0049] In certain embodiments, the laser head 200 is releasably coupledto the laser generator 310 and is releasably coupled to the positioningmechanism 121. In certain embodiments, the positioning mechanism 121 isreleasably coupled to the anchoring mechanism 110, and the controller500 is releasably coupled to the laser base unit 300 and the lasermanipulation system 100. Such embodiments can provide an apparatus 50which can be reversibly assembled and disassembled to facilitatetransportation of the apparatus 50 to locations in proximity to orwithin the structure being processed.

Laser Base Unit

[0050] Certain embodiments of the laser base unit 300 are describedbelow. While the laser base unit 300 is described below as comprisingseparate components, other embodiments can include combinations of twoor more of these components in an integral unit.

[0051] Laser Generator

[0052]FIG. 2 schematically illustrates a laser base unit 300 compatiblewith embodiments described herein. In certain embodiments, the laserbase unit 300 comprises a laser generator 310 and a cooling subsystem320. The laser generator 310 is coupled to a power source (not shown)which provides electrical power of appropriate voltage, phase, andamperage sufficient to power the laser generator 310. The power sourcecan also be portable in certain embodiments, and can operate withoutcooling water, air, or power from the facility at which the apparatus 50is operating. Exemplary power sources include, but are not limited to,diesel-powered electric generators.

[0053] In certain embodiments, the laser generator 310 preferablycomprises an arc-lamp-pumped Nd:YAG laser, but may alternativelycomprise a CO₂laser, a diode laser, a diode-pumped Nd:YAG laser, a fiberlaser, or other types of laser systems. The laser generator 310 can beoperated in either a pulsed mode or a continuous-wave mode. Oneexemplary laser generator 310 in accordance with embodiments describedherein includes a Trumpf 4006D, 4000-watt, continuous-wave laseravailable from Trumpf Lasertechnik GmbH of Ditzingen, Germany. In otherexemplary embodiments, a Yb-doped fiber laser or an Er-doped fiber lasercan be used. Other types of lasers are compatible with embodiments ofthe present invention. Depending on the requirements unique to a givenapplication of the method and apparatus described herein, one skilled inthe art will be able to select the optimal laser for the purposes athand.

[0054] In certain embodiments, the laser generator 310 can be locatedwithin a shipping container for ease of transport and storage. The lasergenerator 310 generates laser light which is preferably deliveredthrough a glass fiber-optic cable from the laser generator 310 to thework location.

[0055] In certain alternative embodiments, the laser generator 310comprises a gas-based CO₂laser which generates laser light by theexcitation of CO₂gas. Such lasers provide high power output (e.g., ˜100W-50 kW) at high efficiencies (e.g., ˜5-13%), and are relativelyinexpensive. The laser light generated by such gas-based CO₂lasers istypically delivered by mirrors and by using a system of ducts or arms todeliver the laser light around bends or corners.

[0056] In certain alternative embodiments, the laser generator 310comprises a diode laser. Such diode lasers are compact compared to gasand Nd:YAG lasers so they can be used in a direct delivery configuration(e.g., in close proximity to the work site). Diode lasers provide highpower (e.g., ˜10 W-6 kW) at high power efficiencies (e.g., ˜25-40%). Incertain embodiments, the laser light from a diode laser can be deliveredvia optical fiber, but with some corresponding losses of power.

[0057] Embodiments using a Nd:YAG laser can have certain advantages overembodiments with CO₂lasers or diode lasers. There is long industrialexperience with Nd:YAG lasers in the materials processing industry andthey provide high power (e.g., ˜100 W-6 kW). Additionally, the laserlight from a Nd:YAG laser can be delivered by optical fiber with onlyslight power losses (e.g., 12%) through a relatively small and longoptical fiber. This permits the staging of the laser generator 310 andsupport equipment in locations relatively far (e.g., about 100 meters)from the work area. Maintaining the laser generator 310 at a distancefrom the surface being processed allows the remainder of the apparatus50 to be smaller and more portable.

[0058] Arc-lamp-pumped Nd:YAG lasers use an arc lamp to excite a Nd:YAGcrystal to generate laser light. Diode-pumped Nd:YAG lasers use diodelasers to excite the Nd:YAG crystal, resulting in an increase in powerefficiency (e.g., ˜10-25%, as compared to less than 5% forarc-lamp-pumped Nd:YAG lasers). This increased efficiency results in thediode-pumped laser having a better beam quality, and requiring a smallercooling subsystem 320. An exemplary arc-lamp-pumped Nd:YAG laser isavailable from Trumpf Lasertechnik GmbH of Ditzingen, Germany.

[0059] Typically, the generation of laser light by the laser generator310 creates excess heat which is preferably removed from the lasergenerator 310 by the cooling subsystem 320 coupled to the lasergenerator 310. The amount of cooling needed is determined by the sizeand type of laser used, but can be about 190 kW of cooling capacity. Thecooling subsystem 320 can utilize excess cooling capability at a jobsite, such as an existing process water or chilled water coolingsubsystem. Alternatively, a unitary cooling subsystem 320 dedicated tothe laser generator 310 is preferably used. Unitary cooling subsystems320 may be air- or liquid-cooled.

[0060] In certain embodiments, as schematically illustrated in FIG. 2,the cooling subsystem 320 comprises a heat exchanger 322 and a waterchiller 324 coupled to the laser 310 to provide sufficient circulatorycooling water to the laser generator 310 to remove the excess heat. Theheat exchanger 322 preferably removes a portion of the excess heat fromthe water, and circulates the water back to the water chiller 324. Thewater chiller 324 cools the water to a predetermined temperature andreturns the cooling water to the laser generator 310. Exemplary heatexchangers 322 and water coolers 324 in accordance with embodimentsdescribed herein are available from Trumpf Lasertechnik GmbH ofDitzingen, Germany.

[0061] Laser Head

[0062] In certain embodiments, the laser head 200 is coupled to thelaser generator 310 and serves as the interface between the apparatus 50and the structure being irradiated. As schematically illustrated by FIG.1, an energy conduit 400 couples the laser head 200 and the lasergenerator 310 and facilitates the transmission of energy from the lasergenerator 310 to the laser head 200. In certain embodiments, the energyconduit 400 comprises an optical fiber which transmits laser light fromthe laser generator 310 to the laser head 200. In other embodiments, theenergy conduit 400 comprises conductors that may include fiber-optic,power, or control wiring cables.

[0063]FIG. 3A schematically illustrates a laser head 200 in accordancewith embodiments described herein. The laser head 200 comprises aconnector 210, at least one optical element 220, a housing 230, and acontainment plenum 240. In certain embodiments, the connector 210 iscoupled to the housing 230, is optically coupled to the laser generator310 via the energy conduit 400, and is adapted to transmit laser lightfrom the laser generator 310. The optical element 220 can be locatedwithin the connector 210, the housing 230, or the containment plenum240. FIG. 3A illustrates an embodiment in which the optical element 220is within the housing 230. In embodiments in which the conduit 400provides laser light to the laser head 200, the laser light istransmitted through the optical element 220 prior to impinging on thestructure being irradiated.

[0064]FIG. 3B schematically illustrates one configuration of a laserhead 200 in accordance with embodiments described herein. The housing230 comprises a distal portion 232, an angle portion 234, and a proximalportion 236. As used herein, the terms “distal” and “proximal” havetheir standard definitions, referring generally to the position of theportion relative to the interaction region. The connector 210 is coupledto the distal portion 232, which is coupled to the angle portion 234,which is coupled to the proximal portion 236, which is coupled to thecontainment plenum 240. Configurations such as that illustrated by FIG.3B can be used for drilling and scabbling the surface of the structure(e.g., concrete wall). Various components of the laser head 200 areavailable from Laser Mechanisms, Inc. of Farmington Hills, Mich.

[0065] In certain embodiments in which the energy conduit 400 comprisesan optical fiber, the connector 210 receives laser light transmittedfrom the laser generator 310 through the optical fiber to the laser head200. In certain such embodiments, the connector 210 comprises a lens 212which collimates the diverging laser light emitted by the conduit 400.The lens 212 can comprise various materials which are transmissive andwill refract the laser light in a desired amount. Such materialsinclude, but are not limited to, borosilicate crown glass (BK7), quartz(SiO₂), zinc selenide (ZnSe), and sodium chloride (NaCl). The materialof the lens 212 can be selected based on the quality, cost, andstability of the material. Borosilicate crown glass is commonly used fortransmissive optics with Nd:YAG lasers, and zinc selenide is commonlyused for transmissive optics with CO₂lasers.

[0066] The lens 212 can be mounted in a removable assembly in certainembodiments to facilitate cleaning, maintenance, and replacement of thelens 212. In addition, the mounting of the lens 212 can be adjustable(e.g., using thumbscrews or Allen hex screws) so as to optimize thealignment and focus of the light beam. In certain embodiments, the lens212 can provide additional modification of the beam profile (e.g.,focussing, beam shape).

[0067] The collimated laser light of certain embodiments is thentransmitted through the laser head 200 via other optical elements withinthe laser head 200. In certain embodiments, the distal portion 232comprises a generally straight first tube through which laser lightpropagates to the angle portion 234, and the proximal portion 236comprises a generally straight second tube through which the laser lightfrom the angle portion 234 propagates. In certain embodiments, thedistal portion 232 contains a lens 233, and the angle portion 234contains a mirror 235 which directs the light through the proximalportion 236 and the containment plenum 240 onto the structure. In otherembodiments, other devices (e.g., a prism) can be used in the angleportion 234 to direct the light through the proximal portion 236 and thecontainment plenum 240 onto the structure.

[0068] The lens 233 can be mounted in a removable assembly in certainembodiments to facilitate cleaning, maintenance, and replacement of thelens 233. In addition, the mounting of the lens 233 can be adjustable(e.g., using thumbscrews or Allen hex screws) so as to optimize thealignment and focus of the light beam. In certain embodiments, the lens233 focuses the light received from the lens 212, while in otherembodiments, the lens 233 can provide additional modification of thebeam profile (e.g., beam shape). Exemplary lenses 233 include, but arenot limited to, a 600-mm focal length silica plano-convex lens (e.g.,Part No. PLCX-50.8-309.1-UV-1064 available from CVI Laser Corp. ofAlbuquerque, N. Mex.). The lens 233 can comprise various materials whichare transmissive and will refract the laser light in a desired amount.Such materials include, but are not limited to, borosilicate crownglass, quartz, zinc selenide, and sodium chloride. Exemplary lensmounting assemblies include, but are not limited to, Part Nos. PLALH0097and PLFLH0119 available from Laser Mechanisms, Inc. of Farmington Hills,Mich.

[0069] In the embodiment schematically illustrated by FIG. 3B in whichthe distal portion 232 is substantially perpendicular to the proximalportion 236, the mirror 235 reflects the light through an angle ofapproximately 90 degrees. Other embodiments are configured to reflectthe light through other angles. The mirror 235 can be mounted on aremovable assembly in certain embodiments to facilitate cleaning,maintenance, and replacement of the mirror 235. In addition, themounting of the mirror 235 can be adjustable (e.g., using thumbscrews orAllen hex screws) so as to optimize the alignment and focus of the lightbeam. In certain embodiments, the mirror 235 can also have a curvatureor otherwise be configured so as to focus the light beam or otherwisemodify the beam profile (e.g., beam shape). Exemplary mirrors 235include, but are not limited to, metal mirrors such as copper mirrors(e.g., Part Nos. PLTRG19 and PLTRC0024 from Laser Mechanisms, Inc. ofFarmington Hills, Mich.), and gold-coated copper mirrors (e.g., Part No.PLTRC0100 from Laser Mechanisms, Inc.). In other embodiments,dielectric-coated mirrors can be used.

[0070]FIG. 3C schematically illustrates another configuration of a laserhead 200 in accordance with embodiments described herein. The housing230 comprises the distal portion 232, a first angle portion 234, asecond angle portion 234′, and the proximal portion 236. The connector210 is coupled to the distal portion 232, which is coupled to the firstangle portion 234, which is coupled to the second angle portion 234′,which is coupled to the proximal portion 236, which is coupled to thecontainment plenum 240. Configurations such as that illustrated by FIG.3C can be used for cutting the structure in spatially constrainedregions (e.g., cutting off portions of a concrete wall near a comer orprotrusion).

[0071] As described above, in certain embodiments, the connector 210comprises a lens 212 and the distal portion 232 is tubular and containsa lens 233. The first angle portion 234 of the embodiment illustrated byFIG. 3C contains a first mirror 235 which directs the light to thesecond angle portion 234′ which contains a second mirror 235′. Thesecond mirror 235′ directs the light through the proximal portion 236,which can be tubular, and through the containment plenum 240 onto thestructure.

[0072] In the embodiment schematically illustrated by FIG. 3C, the firstmirror 235 reflects the light through an angle of approximately 90degrees and the second mirror 235′ reflects the light through an angleof approximately −90 degrees such that the proximal portion 236 issubstantially parallel to the distal portion 232. In such embodiments,the light emitted by the containment plenum 240 is substantiallyparallel to, but displaced from, the light propagating through thedistal portion 232. Other embodiments have the first mirror 235 and thesecond mirror 235′ configured to reflect the light through other angles.Certain embodiments comprise a straight tubular portion between thefirst angle portion 234 and the second angle portion 234′ to provideadditional displacement of the light emitted by the containment plenum240 from the light propagating through the distal portion 232.

[0073] In certain embodiments, the coupling between the distal portion232 and the first angle portion 234 is rotatable. In certain otherembodiments, the coupling between the first angle portion 234 and thesecond angle portion 234′ is rotatable. These rotatable couplings cancomprise swivel joints which can be locked in position by thumbscrews.Such embodiments provide additional flexibility in directing the lightemitted by the containment plenum 240 in a selected direction. Incertain embodiments, the selected direction is non-planar with the lightpropagating through the distal portion 232.

[0074] As described above, one or both of the first mirror 235 and thesecond mirror 235′ can be mounted on a removable assembly in certainembodiments to facilitate cleaning, maintenance, and replacement. Inaddition, the mountings of the first mirror 235 and/or the second mirror235′ can be adjustable (e.g., using thumbscrews or Allen hex screws) soas to optimize the alignment and focus of the light beam. In certainembodiments, one or both of the first mirror 235 and the second mirror235′ can also have a curvature or otherwise be configured so as to focusthe light beam or otherwise modify the beam profile (e.g., beam shape).

[0075] In certain embodiments, one or more of the optical elements 220within the laser head 200 (e.g., lens 212, lens 233, mirror 235, mirror235′) are water-cooled or air-cooled. Cooling water can be supplied by aheat exchanger located near the laser head 200 and dedicated toproviding sufficient water flow to the laser head 200. In certain suchembodiments, the conduits for the cooling water for each of the opticalelements 220 can be connected in series so that the cooling water flowssequentially in proximity to the optical elements 220. In otherembodiments, the conduits are connected in parallel so that separateportions of the cooling water flow in proximity to the various opticalelements 220. Exemplary heat exchangers include, but are not limited toa Miller Coolmate™ 4, available from Miller Electric Manufacturing Co.of Appleton, Wis. The flow rate of the cooling water is preferably atleast approximately 0.5 gallons per minute.

[0076] In certain embodiments, the laser head 200 comprises acontainment plenum 240 coupled to the proximal portion 236 and whichinterfaces with the structure. In certain embodiments, the containmentplenum 240 is adapted to confine material (e.g., debris and fumesgenerated during laser processing) removed from the structure and removethe material from the interaction region. The containment plenum 240 canalso be further adapted to reduce noise and light emitted from theinteraction region out of the containment plenum 240 (e.g., into thenominal hazard zone (“NHZ”) of the laser). One goal of the containmentplenum 240 can be to ensure that no laser radiation in excess of theaccessible emission limit (“AEL”) or maximum-permissible exposure(“MPE”) limit reaches the eye or skin of any personnel.

[0077]FIG. 4 schematically illustrates a cross-sectional view of acontainment plenum 240 in accordance with embodiments described herein.The containment plenum 240 of FIG. 4 comprises a plenum housing 242, awindow 243, a nozzle 244, a resilient interface 246, an extraction port248, and a compressed gas inlet 249. The plenum housing 242 can becoupled to a source of laser light (e.g., the proximal portion 236 ofthe laser head 200) and can provide structural support for the othercomponents of the containment plenum 240. Exemplary materials for theplenum housing 242 include, but are not limited to, metals (e.g.,aluminum, steel) which can be in the form of thin flexible sheets,ceramic materials, glass or graphite fibers, and fabric made from glassor graphite fibers. In certain embodiments, the plenum housing 242 iseither air-cooled or water-cooled to reduce heating of the plenumhousing 242. Coolant conduits for the plenum housing 242 can be coupledin series or in parallel with the coolant conduits for other componentsof the laser head 200.

[0078] The window 243 can be positioned upstream of the nozzle 244 andwithin the propagation path of the laser light from the proximal portion236 to the structure. As used herein, the terms “downstream” and“upstream” have their ordinary meanings referring to the propagationdirection of the laser light and to the direction opposite to thepropagation direction of the laser light, respectively. In suchembodiments, the light propagating through the containment plenum 240reaches the window 243 prior to reaching the nozzle 244. In suchembodiments in which the light propagates downstream through the window243, the window 243 is substantially transparent to the laser light. Thewindow 243 can be mounted within the plenum housing 242 to transmit thelaser light in the downstream direction. Exemplary windows 243 include,but are not limited to, a silica window (e.g., Part No.W2-PW-2037-UV-1064-0 available from CVI Laser Corp. of Albuquerque, N.Mex.).

[0079] Dust and/or dirt on the optical elements of the laser head 200can absorb an appreciable fraction of the laser light, resulting innonuniform heating which can damage the optical elements. In certainembodiments, the window 243 is mounted within the plenum housing 242 toprovide a barrier to the upstream transport of dust, smoke, or otherparticulate matter generated by the interaction of the laser light andthe structure. In this way, the window 243 can facilitate protection ofthe upstream optical elements within the other portions of the laserhead 200.

[0080] The window 243 can be mounted in a removable assembly in certainembodiments to facilitate cleaning, maintenance, and replacement of thewindow 243. In certain embodiments, the window 243 focuses the lightreceived from the proximal portion 236, while in other embodiments, thewindow 243 can provide additional modification of the beam profile(e.g., beam shape). In such embodiments, the mounting of the window 243can be adjustable (e.g., using thumbscrews or Allen hex screws) so as tooptimize the alignment and focus of the light beam. Exemplary windowmounting assemblies include, but are not limited to, Part Nos. PLALH0097and PLFLH0119 available from Laser Mechanisms, Inc. of Farmington Hills,Mich. In certain embodiments, the window 243 is either air-cooled orwater-cooled.

[0081] The laser light transmitted through the window 243 is emittedthrough the nozzle 244 towards the interaction region of the structure.The laser light can be focussed near the opening of the nozzle 244.Exemplary materials for the nozzle 244 include, but are not limited tometals (e.g., copper). In certain embodiments, the nozzle 244 is eitherair-cooled or water-cooled to reduce heating of the nozzle 244. Coolantconduits for the nozzle 244 can be coupled in series or in parallel withthe coolant conduits for other components of the laser head 200.

[0082] The laser light propagating through the nozzle 244 preferablydoes not impinge the nozzle 244 (termed “clipping”) to avoid excessivelyheating and damaging the nozzle 244. Improper alignment of the laserlight through the laser head 200 can cause clipping. The opening of thenozzle 244 can be sufficiently large so that the laser light does notappreciably interact with the nozzle 244. In certain embodiments, thenozzle 244 is approximately 0.3 inches in diameter.

[0083] In certain embodiments, the resilient interface 246 of thecontainment plenum 240 is adapted to contact the structure and tosubstantially surround the interaction region, thereby facilitatingconfinement and removal of material from the interaction region. Inaddition, the resilient interface 246 can facilitate blocking lightand/or sound from escaping outside the containment plenum 240. Exemplaryresilient interfaces 246 include, but are not limited to, a wire brush.

[0084] In certain embodiments, the extraction port 248 of thecontainment plenum 240 is adapted to extract an appreciable portion ofthe material (e.g., gas, vapor, dust, and debris) generated within theinteraction region during operation. The extraction port 248 can becoupled to a vacuum generator (not shown) which creates a vacuum to pullmaterial (e.g., airborne particulates, gases, and vapors) from theinteraction region. In this way, the extraction port 248 can provide apathway for removal of the material from the containment plenum 240.

[0085] In certain embodiments, the compressed gas inlet 249 is adaptedto provide compressed gas (e.g., air) to the containment plenum 240. Incertain embodiments, the compressed gas inlet 249 is fluidly coupled tothe nozzle 244 which is adapted to direct a compressed gas stream to theinteraction region. In certain embodiments, compressed gas flowscoaxially with the laser light through the nozzle 244. The window 243 ofcertain embodiments provides a surface against which the compressed gasexerts pressure. In this way, the compressed gas can flow through thenozzle 244 to the interaction region at a selected pressure andvelocity.

[0086] The compressed gas flowing from the compressed gas inlet 249through the nozzle 244 can be used to deter dust, debris, smoke, andother particulate matter from entering the nozzle 244. In this way, thecompressed gas can facilitate protection of the window 243 from suchparticulate matter. In addition, the compressed gas can be directed bythe nozzle 244 to the interaction region so as to facilitate removal ofmaterial from the interaction region. The nozzle 244 can be used in thismanner in embodiments in which the structure includes concrete with ahigh percentage of Si, so that the resultant glassy slag is sufficientlyviscous and more difficult to remove from the interaction region.

[0087] In certain embodiments, the compressed air is substantially freeof oil, moisture, or other contaminants to avoid contaminating thesurface of the window 243 and potentially damaging the window 243 bynonuniform heating. An exemplary source of instrument quality (“IQ”)compressed air is the 300-IQ air compressor available fromIngersoll-Rand Air Solutions Group of Davidson, N.C. The source ofcompressed air preferably provides air at a sufficient flow ratedetermined in part by the length of the hose delivering the air, and thenumber of components using the air and their requirements.

[0088] In certain embodiments, the air compressor can be locatedhundreds of feet away from the laser head 200. In such embodiments, thesource of compressed air can comprise an air dryer to reduce the amountof moisture condensing in the air conduits or hoses between the aircompressor and the laser head 200. An exemplary air dryer in accordancewith embodiments described herein is the 400 HSB air dryer availablefrom Zeks Compressed Air Solutions of West Chester, Pa.

[0089] In certain embodiments, as schematically illustrated in FIG. 5,the laser head 200 comprises a sensor 250 adapted to measure therelative distance between the laser head 200 and the interaction region.FIG. 5 schematically illustrates an embodiment in which the containmentplenum 240 comprises the sensor 250, although other locations of thesensor 250 are also compatible with embodiments described herein. Asmaterial is removed from the structure, the interaction region extendsinto the structure. The sensor 250 then provides a measure of the depthof the interaction region from the surface of the structure. The sensor250 can use various technologies to determine this distance, including,but not limited to, acoustic sensors, infrared sensors, tactile sensors,and imaging sensors. In certain embodiments in which laser scabbling ormachining is performed, a sensor 250 comprising a diode laser andutilizing triangulation could be used to determine the distance betweenthe laser head 200 and the surface being processed. Such a sensor 250can also provide a measure of the amount of material removed from thesurface.

[0090] In certain embodiments, the sensor 250 is coupled to thecontroller 500, and the controller 500 is adapted to transmit controlsignals to the laser base unit 300 in response to signals from thesensor 250. The laser base unit 300 can be adapted to adjust one or moreparameters of the laser light in response to the control signals. Inthis way, the depth information from the sensor 250 can be used inreal-time to adjust the focus or other parameters of the laser light.

[0091] In other embodiments, the controller 500 is adapted to transmitcontrol signals to the laser manipulation system 100 in response tosignals from the sensor 250. The laser manipulation system 100 isadapted to adjust the relative distance between the laser head 200 andthe interaction region in response to the control signals. In addition,the laser manipulation system 100 can be adapted to adjust the positionof the laser head 200 along the surface of the structure in response tothe control signals. In this way, the depth information from the sensor250 at a first location can be used in real-time to move the laser lightto another location along the surface once a desired depth at the firstlocation is achieved.

[0092] In other embodiments, the sensor 250 is used in conjunction withstatistical methods to determine the depth of the interaction region. Insuch embodiments, the sensor 250 is first used in a measurement phase todevelop statistical data which correlates penetration depths withcertain processing parameters (e.g., material being processed, lightintensity). During the measurement phase, selected processing parametersare systematically varied for processing a test or sample surfacesindicative of the surfaces of the structure to be processed. The sensor250 is used in the measurement phase to determine the depth of theinteraction region corresponding to these processing parameters. Incertain such embodiments, the sensor 250 can be separate from the laserhead 200, and can be used during the processing of the structure orduring periods when the processing has been temporarily halted in orderto measure the depth of the interaction region. Exemplary sensors 250compatible with such embodiments include, but are not limited to,calipers or other manual measuring devices which are inserted into theresultant hole to determine the depth of the interaction region.

[0093] In certain embodiments, the controller 500 contains thisresulting statistical data regarding the correlation between theprocessing parameters and the depth of the interaction region. During asubsequent processing phase, the structure is processed, but rather thanusing the sensor 250 at this time, the controller 500 can be adapted todetermine the relative distance by accessing the statistical datacorresponding to the particular processing parameters being used. Suchan approach represents a reliable and cost-effective approach fordetermining the depth of the interaction region while processing thestructure.

[0094] In alternative embodiments, the sensor 250 is adapted to providea measure of the distance between the laser head 200 and the surface ofthe structure. In such embodiments, the sensor 250 can be adapted toprovide a fail condition signal to the controller 500 upon detection ofthe relative distance between the laser head 200 and the structureexceeding a predetermined distance. Such a fail condition may resultfrom the apparatus 50 inadvertently becoming detached from thestructure. The controller 500 can be adapted to respond to the failcondition signal by sending appropriate signals to the laser base unit300 to halt the transmission of energy between the laser base unit 300and the laser head 200. In certain embodiments, the transmission ispreferably halted when the laser head 200 is further than one centimeterfrom the surface of the structure. In this way, the apparatus 50 canutilize the sensor 250 to insure that laser light is not emitted unlessthe containment plenum 240 is in contact with the structure. In certainembodiments, the sensor 250 comprises a proximity switch which contactsthe surface of the structure while the apparatus 50 is attached to thestructure.

Laser Manipulation System

[0095] In certain embodiments, the laser manipulation system 100 servesto accurately and repeatedly position the laser head 200 in relation tothe structure so as to provide articulated robotic motion generallyparallel to the surface to be processed. To do so, the lasermanipulation system 100 can be releasably affixed to the structure to beprocessed, and can then accurately move the laser head 200 in proximityto that surface. FIGS. 6A and 6B schematically illustrate two oppositeelevated perspectives of an embodiment in which the laser manipulationsystem 100 comprises an anchoring mechanism 110 adapted to be releasablycoupled to the structure and a positioning mechanism 121 coupled to theanchoring mechanism 110 and coupled to the laser head 200. In certainembodiments, the laser manipulation system 100 can be advantageouslydisassembled and reassembled for transport, storage, or maintenance.

[0096] Anchoring Mechanism

[0097] Certain embodiments of the laser manipulation system 100 comprisean anchoring mechanism 110 to releasably affix the laser manipulationsystem 100 to the structure to be processed. The anchoring mechanism 110can be adapted to be releasably coupled to the structure and cancomprise one or more attachment interfaces 111.

[0098] In the embodiment schematically illustrated in FIG. 6B, theanchoring mechanism 110 comprises a pair of attachment interfaces 111.Each attachment interface 111 comprises at least one resilient vacuumpad 112, at least one interface mounting device 114, at least one vacuumconduit 116, at least one mounting connector 118, and a coupler 119adapted to couple the attachment interface 111 of the anchoringmechanism 110 to the positioning mechanism 121. While the embodimentschematically illustrated in FIGS. 6A and 6B have two vacuum pads 112for each of the two attachment interfaces 111, other embodiments utilizeany configuration or number of attachment interfaces 111 and vacuum pads112.

[0099] In the embodiment illustrated by FIG. 7, two vacuum pads 112 arecoupled to the interface mounting device 114. In certain embodiments,each vacuum pad 112 comprises a circular rubber pad which forms aneffectively air-tight region when placed on the structure. Each vacuumpad 112 is fluidly coupled to at least one vacuum generator (not shown)via a vacuum conduit 116 (e.g., a flexible hose). The vacuum generatormay use fluid power (e.g., compressed air) to generate the vacuum, or itmay use an external vacuum source. The vacuum generator draws air outfrom the air-tight region between the vacuum pad 112 and the structurevia the vacuum conduit 116, thereby creating a vacuum within theair-tight region. Atmospheric pressure provides a force which reversiblyaffixes the vacuum pad 112 to the structure.

[0100] The interface mounting device 114 comprises a rigid metal supportupon which is mounted the vacuum pads 112, the mounting connector 118,and the coupler 119. In certain embodiments, the mounting connector 118can comprise a ground-based support connector 118 a adapted to bereleasably attached to a ground-based support system 700, as describedmore fully below. In other embodiments, the mounting connector 118 cancomprise at least one suspension-based support connector 118 b adaptedto be releasably attached to a suspension-based support system 800, asdescribed more fully below. The coupler 119 is adapted to releasablycouple the interface mounting device 114 to the positioning mechanism121. In certain embodiments, the coupler 119 comprises at least oneprotrusion which is connectable to at least one corresponding recess inthe positioning mechanism 121.

[0101] In alternative embodiments, the anchoring mechanism 110 cancomprise other technologies for anchoring the apparatus 50 to thestructure to be processed. These other technologies include, but are notlimited to, a winch, suction devices (e.g., cups, gekkomats, or skirts)affixed to the apparatus 50 or on quasi-tank treads, mobile scaffoldingsuspended from the structure, and a rigid ladder. These technologies canalso be used in combination with one another in certain embodiments ofthe anchoring mechanism 110.

[0102] Positioning Mechanism

[0103] Certain embodiments of the laser manipulation system 100 comprisea positioning mechanism 121 to accurately move the laser head 200 whilein proximity to the structure to be processed. FIG. 8 schematicallyillustrates an exploded view of one embodiment of the positioningmechanism 121 along with the attachment interfaces 111 of the anchoringmechanism 110. The positioning mechanism 121 of FIG. 8 comprises afirst-axis position system 130, a second-axis position system 150, aninterface 140, and a laser head receiver 220. The first-axis positionsystem 130 is releasably coupled to the attachment interfaces 111 of theanchoring mechanism 110 by at least one coupler 132. The interface 140(comprising a first piece 140 a and a second piece 140 b in theembodiment of FIG. 8) releasably couples the second-axis position system150 to the first-axis position system 130. The laser head receiver 220is releasably coupled to the second-axis position system 150, and isadapted to be releasably coupled to the housing 230 of the laser head200.

[0104] In certain embodiments, the first-axis position system 130comprises at least one coupler 132 having a recess which is releasablyconnectable to at least one corresponding protrusion of the coupler 119of the anchoring mechanism 110. Such embodiments are advantageouslydisassembled and reassembled for transport, storage, or maintenance ofthe positioning mechanism 121. Other embodiments can have the first-axisposition system 130 fixedly coupled to the anchoring mechanism 110.

[0105] In certain embodiments, the first-axis position system 130 movesthe laser head 200 in a first direction substantially parallel to thesurface of the structure. In the embodiment schematically illustrated byFIG. 9, the first-axis position system 130 further comprises a firstrail 134, a first drive 136, and a first stage 138. The first stage 138is movably coupled to the first rail 134 under the influence of thefirst drive 136. The first piece 140 a of the interface 140 is fixedlycoupled to the first stage 138 so that the first drive 136 can be usedto move the interface 140 along the first rail 134. In certainembodiments, the first-axis position system 130 further comprisessensors, limit switches, or other devices which provide informationregarding the position of the first stage 138 along the first rail 134.This information can be provided to the controller 500, which is adaptedto transmit control signals to the first drive 136 or other componentsof the laser manipulation system 100 in response to this information.

[0106] Exemplary first drives 136 include, but are not limited to,hydraulic drives, pneumatic drives, electromechanical drives, screwdrives, and belt drives. First rails 134, first drives 136, and firststages 138 compatible with embodiments described herein are availablefrom Tol-O-Matic, Inc. of Hamel, Minn. Other types and configurations offirst rails 134, first drives 136, and first stages 138 are alsocompatible with embodiments described herein.

[0107] In certain embodiments, the second-axis position system 150 movesthe laser head 200 in a second direction substantially parallel to thesurface of the structure. The second direction in certain embodiments issubstantially perpendicular to the first direction of the first-axisposition system 130. In the embodiment schematically illustrated by FIG.10, the second-axis position system 150 comprises a second rail 152, asecond drive 154, and a second stage 156. In certain embodiments, thefirst-axis position system 130 and the second-axis position system 150provide linear movements of the laser head 200. In other embodiments,the first-axis position system 130 and the second-axis position system150 provide circular and axial movements of the laser head 200,respectively.

[0108] In certain embodiments, the second stage 156 is movably coupledto the second rail 152 under the influence of the second drive 154. Thelaser head receiver 220 is releasably coupled to the second stage 156 sothat the second drive 154 can be used to move the laser head receiver220 along the second rail 152. In certain embodiments, the second-axisposition system 150 further comprises sensors, limit switches, or otherdevices which provide information regarding the position of the secondstage 156 along the second rail 152. This information can be provided tothe controller 500, which is adapted to transmit control signals to thesecond drive 154 or other components of the laser manipulation system100 in response to this information.

[0109] Exemplary second drives 154 include, but are not limited to,hydraulic drives, pneumatic drives, electromechanical drives, screwdrives, and belt drives. Second rails 152, second drives 154, and secondstages 156 compatible with embodiments described herein are availablefrom Tol-O-Matic, Inc. of Hamel, Minn. Other types and configurations ofsecond rails 152, second drives 154, and second stages 156 are alsocompatible with embodiments described herein.

[0110] In certain embodiments, the second rail 152 is fixedly coupled tothe second piece 140 b of the interface 140. The second piece 140 b cancomprise at least one recess which is releasably connectable to at leastone corresponding protrusion of the first piece 140 a of the interface140. Such embodiments are advantageously disassembled and reassembledfor transport, storage, or maintenance of the positioning mechanism 121.In other embodiments, the interface 140 can be made of a single piecewhich is releasably coupled to one or both of the first stage 138 andthe second rail 152. Other embodiments are not configured for convenientdisassembly (e.g., having an interface 140 made of a single piece andthat is fixedly coupled to both the first stage 138 and the second rail152).

[0111] In certain embodiments, the interface 140 comprises a tiltmechanism 144 to adjust the relative orientation between the first rail134 and the second rail 152. As schematically illustrated in FIG. 11A,the first piece 140 a of the interface 140 is coupled to the first stage138 on the first rail 134, and comprises a pair of protuberances 142adapted to couple with corresponding recesses of the second piece 140 bof the interface 140. The tilt mechanism 144 comprises a first plate145, a hinge 146, a second plate 147, and a pair of support braces 148.The first plate 145 is fixedly mounted to the first stage 138 and issubstantially parallel to the surface upon which the anchoring mechanism110 is mounted. The second plate 147 is pivotally coupled to the firstplate 145 by the hinge 146, and can be locked in place by the supportbraces 148.

[0112] In FIG. 11A, the tilt mechanism 144 is configured so that thefirst plate 145 and the second plate 147 are substantially parallel toone another. In this configuration, the plane of movement defined by thefirst direction and the second direction of the laser head 200 issubstantially parallel to the surface upon which the anchoring mechanism110 is coupled. In FIG. 11B, the tilt mechanism 144 is configured sothat the second plate 147 is at a non-zero angle (e.g., 90 degrees)relative to the first plate 145. In this configuration, the plane ofmovement defined by the first direction and the second direction of thelaser head 200 is at a non-zero angle relative to the surface upon whichthe anchoring mechanism 110 is coupled.

[0113] In certain embodiments, the laser head receiver 220 is releasablycoupled the housing 230 of the laser head 200. FIG. 12 schematicallyillustrates a laser head receiver 220 compatible with embodimentsdescribed herein. The laser head receiver 220 is coupled to the secondstage 156 and comprises a releasable clamp 222 and a third-axis positionsystem 224. The clamp 222 is adapted to hold the housing 230 of thelaser head 200. The third-axis position system 224 is adapted to adjustthe relative distance between the laser head 200 and the structure beingprocessed. In certain embodiments, the third-axis position system 224comprises a screw drive which moves the clamp 222 substantiallyperpendicularly to the second rail 152. In certain embodiments, asschematically illustrated by FIG. 12, the screw drive is manuallyactuated by a handle 226, which can be rotated to move the clamp 222. Inother embodiments, the screw drive is automatically controlled byequipment responsive to control signals from the controller 500.

[0114] Ground-Based Support System

[0115] In certain embodiments, the apparatus 50 can be utilized with aground-based support system 700 which is releasably coupled to theapparatus 50. The interface mounting devices 114 can each comprise aground-based support connector 118 a adapted to releasably couple to theground-based support system 700. The ground-based support system 700advantageously attaches to various types of external boom systems, suchas commercially-available lifting- or positioning-type systems, whichcan support some of the weight of the apparatus 50, thereby reducing theweight load supported by the anchoring mechanism 110. The ground-basedsupport system 700 can be used to facilitate use of the apparatus 50 onsubstantially vertical surfaces (e.g., walls) or on substantiallyhorizontal surfaces (e.g., ceilings).

[0116] In certain embodiments, the ground-based support system 700includes a support structure 710 such as that schematically illustratedin FIG. 13. The support structure 710 of FIG. 13 comprises a boomconnector 712, a rotational mount 714, a spreader member 716, a pair ofprimary posts 718, and a pair of auxiliary posts 720. The boom connector712 is adapted to attach to a selected external boom system. Therotational mount 714 is adapted to be rotatably coupled to the boomconnector 712 and fixedly coupled to the spreader member 716 so that theboom connector 712 can be advantageously rotated relative to the supportstructure 710.

[0117] The primary posts 718 are coupled to the spreader member 716 andare substantially parallel to one another. Each of the primary posts 718is adapted to be coupled to one of the ground-based support connectors118 a of the interface mounting devices 114. The primary posts 718 caneach be coupled to the spreader member 716 at various positions so thatthey are aligned with the ground-based support connectors 118 a. Eachprimary post 718 is also coupled to, and is substantially perpendicularto, an auxiliary post 720. In such embodiments, rather than having theprimary posts 718 coupled to the ground-based support connectors 118 a,the auxiliary posts 720 can be coupled to the ground-based supportconnectors 118 a, thereby effectively rotating the support structure 710by 90 degrees relative to the anchoring mechanism 110. Such embodimentsadvantageously provide adjustability for processing variousconfigurations of structures and to permit alternative configurationsbest suited for particular applications.

[0118] Suspension-Based Support System

[0119] Alternatively, the apparatus 50 can be utilized with asuspension-based support system 800 which is releasably coupled to theapparatus 50. The interface mounting devices 114 can each comprise atleast one suspension-based support connector 118 b adapted to releasablycouple to the suspension-based support system 800. The suspension-basedsupport system 800 advantageously supports some of the weight of theapparatus 50, thereby reducing the weight load supported by theanchoring mechanism 110. The suspension-based support system 800 can beused to facilitate use of the apparatus 50 on substantially verticalsurfaces (e.g., outside walls).

[0120] In certain embodiments, as schematically illustrated in FIG. 14A,the suspension-based support system 800 comprises a winch 810, a primarycable 812, and a pair of secondary cables 814. The winch 810 ispositioned on the roof or other portion of a structure to be processed.The winch 810 is coupled to the primary cable 812, which is coupled tothe secondary cables 814. The secondary cables 814 are each coupled to asuspension-based support connector 118 b of the interface mountingdevice 114 of the anchoring mechanism 110. FIG. 14B schematicallyillustrates one embodiment of the apparatus having the suspension-basedsupport connectors 118 b. The apparatus 50 can then be lowered or raisedby utilizing the winch 810 to shorten or lengthen the working length ofthe primary cable 814. In alternative embodiments, the ground-basedsupport connectors 118 a can be configured to serve also as thesuspension-based support connectors 118 b.

Controller

[0121] The controller 500 is electrically coupled to the laser base unit300 and to the laser manipulation system 100, and is adapted to transmitcontrol signals to the laser base unit 300 and to the laser manipulationsystem 100. FIG. 15 schematically illustrates an embodiment of acontroller 500 in accordance with embodiments described herein. Thecontroller 500 comprises a control panel 510, a microprocessor 520, alaser generator interface 530, a positioning system interface 540, asensor interface 550, and a user interface 560.

[0122] In certain embodiments, the control panel 510 includes a mainpower supply, main power switch, emergency power off switch, and variouselectrical connectors adapted to couple to other components of thecontroller 500. The control panel 510 is adapted to be coupled to anexternal power source (not shown in FIG. 15) and to provide power tovarious components of the apparatus 50.

[0123] In certain embodiments, the microprocessor 520 can comprise aProgrammable Logic Controller microprocessor (PLC). PLCs are rugged,reliable, and easy-to-configure, and exemplary PLCs are available fromRockwell Automation of Milwaukee, Wis., Schneider Electric of Palatine,Ill., and Siemens AG of Munich, Germany. In alternative embodiments, themicroprocessor 520 comprises a personal computer microprocessor, orPC/104 embedded PC modules which provide easy and flexibleimplementation. The microprocessor 520 can be adapted to respond toinput signals from the user (via the user interface 560), as well asfrom various sensors of the apparatus 50 (via the sensor interface 550),by transmitting control signals to the other components of the apparatus50 (via the laser generator interface 530 and the positioning systeminterface 540) to achieve the desired cutting or drilling pattern.

[0124] The microprocessor 520 can be implemented in hardware, software,or a combination of the two. When implemented in a combination ofhardware and software, the software can reside on a processor-readablestorage medium. In addition, the microprocessor 520 of certainembodiments comprises memory to hold information used during operation.

[0125] In certain embodiments, the laser generator interface 530 iscoupled to the laser base unit 300 and is adapted to transmit controlsignals from the microprocessor 520 to various components of the laserbase unit 300. For example, the laser generator interface 530 cantransmit control signals to the laser generator 310 to set desiredoperational parameters, including, but not limited to, laser poweroutput levels and laser pulse profiles and timing. In addition, thelaser generator interface 530 can transmit control signals to thecooling subsystem 320 to set appropriate cooling levels, the source ofcompressed gas coupled to the compressed gas inlet 249 of thecontainment plenum 240, or to the vacuum generator coupled to theextraction port 248.

[0126] In certain embodiments, the positioning system interface 540 iscoupled to the positioning mechanism 121 of the laser manipulationsystem 100 and is compatible with the first-axis position system 130 andsecond-axis position system 150, as described above. In certain suchembodiments, the positioning system interface 540 comprisesservo-drivers for the first-axis position system 130 and the second-axisposition system 150. The servo-drivers are preferably responsive tocontrol signals from the microprocessor 520 to generate driving voltagesand currents for the first drive 136 and the second drive 154. In thisway, the controller 500 can determine how the laser head 200 is scannedacross the surface of the structure. In certain embodiments, theservo-drivers receive their power from the control panel 510 of thecontroller 500. In embodiments in which the positioning mechanism 121further comprises a third-axis position system, the positioning systeminterface 540 further comprises an appropriate servo-driver so that thecontroller 500 can determine the relative distance between the laserhead 200 and the structure surface being processed.

[0127] In certain embodiments, the sensor interface 550 is coupled tovarious sensors (not shown in FIG. 15) of the apparatus 50 which providedata upon which operation parameters can be selected or modified. Forexample, as described above, the laser head 200 can comprise a sensor250 adapted to measure the relative distance between the laser head 200and the interaction region. The sensor interface 550 of such embodimentsreceives data from the sensor 250 and provide this data to themicroprocessor 520. The microprocessor 520 can then adjust variousoperational parameters of the laser base unit 300 and/or the lasermanipulation system 100, as appropriate, in real-time. Other sensorswhich can be coupled to the controller 500 via the sensor interface 550include, but are not limited to, proximity sensors to confirm that thelaser head 200 is in position relative to the surface being processed,temperature or flow sensors for the various cooling, compressed air, andvacuum systems, and rebar detectors (as described more fully below).

[0128] In certain embodiments, the user interface 560 adapted to provideinformation regarding the apparatus 50 to the user and to receive userinput which is transmitted to the microprocessor 520. In certainembodiments, the user interface 560 comprises a control pendant 570which is electrically coupled to the microprocessor 520. Asschematically illustrated in FIG. 16, in certain embodiments, thecontrol pendant 570 comprises a screen 572 and a plurality of buttons574.

[0129] The screen 572 can be used to display status information andoperational parameter information to the user. Exemplary screens 572include, but are not limited to, liquid-crystal displays. The buttons574 can be used to allow a user to input data which is used by themicroprocessor 520 to set operational parameters of the apparatus 50.Other embodiments can use other technologies for communicating userinput to the apparatus 50, including, but not limited to, keyboard,mouse, touchpad, and potentiometer knobs and/or dials. In certainembodiments, the control pendant 570 is hard-wired to the apparatus 50,while in other embodiments, the control pendant 570 communicatesremotely (e.g., wirelessly) with the apparatus 50.

[0130] In certain embodiments, the control pendant 570 further comprisesan emergency stop button and a cycle stop button. Upon pressing theemergency stop button, the apparatus 50 immediately ceases all movementand the laser irradiation is immediately halted. Upon pressing the cyclestop button, the apparatus 50 similarly ceases all movement and haltslaser irradiation corresponding to the cutting sequence being performed,but the user is then provided with the option to return to the beginningof the cutting sequence or to re-start cutting at the spot where thecutting sequence was stopped. In certain embodiments, the controlpendant 570 further comprises a “dead man switch,” which must bemanually actuated by the user for the apparatus 50 to perform. Such aswitch provides a measure of safety by ensuring that the apparatus 50 isnot run without someone actively using the control pendant 570.

[0131]FIGS. 17A-17H illustrate a set of exemplary screen displays of thecontrol pendant 570. The function of each of the buttons 574 along theleft and right sides of the screen 572 is dependent on the operationmode of the apparatus 50. Each of the screen displays providesinformation regarding system status along with relevant informationregarding the current operation mode.

[0132] The “MAIN SCREEN” display of FIG. 17A comprises a “MachineStatus” field, a “System Status” field, and label fields correspondingto the functions of some or all of the buttons 574 of the controlpendant 570. The “Machine Status” field includes a text message whichdescribes what the apparatus 50 is doing and what the user may do next.The “System Status” field includes a box which shows the operationalmode of the apparatus 50. In the example illustrated by FIG. 17A, theapparatus is in “maintenance mode.” The “System Status” field alsoincludes a plurality of status boxes which indicate the status ofvarious components of the apparatus 50, including, but not limited to,the vacuum pads 112 of the anchoring system 110, the air or vacuumpressure, the first-axis position system 130, and the second-axisposition system 150. The “System Status” field also indicates whetherthere are any faults sensed with the laser base unit 300. In certainembodiments, nominal status of a component is shown with thecorresponding status box as green. The ready state of the apparatus 50is illustrated by having all the system status boxes appear as green. Ifthe status of one of these components is outside operational parameters,the corresponding status box is shown as red, and the system interlocksare enabled, preventing operation of the apparatus 50. Upon startup, thesystem interlocks are enabled and must be cleared prior to operation ofthe apparatus 50. The text messages of the “Machine Status” fieldprovide information regarding the actions to be performed to place theapparatus 50 within operational parameters and to clear the systeminterlocks. Upon clearing all the system interlocks, the “MachineStatus” field will indicate that the apparatus 50 is ready to be used.

[0133] The “SELECT OPERATION SCREEN” display of FIG. 17B comprises the“Machine Status” field, the “System Status” field, and the label fieldscorresponding to the functions of some or all of the buttons 574. The“System Status” field includes information regarding the position of thelaser head 200 along the first-axis position system 130 (referred to asthe long axis) and the second-axis position system 150 (referred to asthe short axis). Some of the buttons 574 are configured to enablevarious operations. For example, four buttons 574 are configured toenable four different operations: circle, pierce, straight cut, andsurface keying, as illustrated in FIG. 17B.

[0134]FIG. 17C shows a “CIRCLE SETUP/OPERATION SCREEN” display whichprovides information regarding the circle operation of the apparatus 50in which the laser head 200 moves circularly to cut a circular patternto a desired depth into the surface of the structure to be processed. Incertain embodiments, the circle operation can be used for “trepanning,”whereby a solid circular core is cut and removed from the surface,leaving a circular hole.

[0135] A “Circle Status” field provides information regarding the statusof the circle operation and corresponding instructions to the user. Thestarting position of the laser head 200 along the first-axis positionsystem 130 and the second-axis position system 150 are provided in the“System Status” field. A “Circle Parameters” field provides informationregarding various parameters associated with the cutting of a circularpattern, including, but not limited to, the number of revolutions aroundthe circular pattern, the diameter, time period that the cutting will beperformed, the speed of motion of the laser head 200 around the circle,and the laser base unit (LBU) program number. In certain embodiments,the LBU program number corresponds to operational parameters of thelaser head 200 including, but not limited to, beam focus and intensity.

[0136] In certain embodiments, the various parameters can be changed bytouching the parameter on the screen 572, upon which a numerical keypadwill pop up on the screen 572 so that a new value can be entered. Foreach parameter, the “set point” value corresponds to the value currentlyin memory and the last value that was entered. The “status” valuecorresponds to the current value being selected. Upon saving the newparameter value, the “status” and “set point” values are the same.Pressing the button 574 a labeled “Auto/Dry Run” will initiate thecircular movement of the laser head 200 without activating the laserbeam, to ensure the desired motion. Pressing the button 574 b labeled“Cycle Start” will initiate the cutting of the circular pattern,including both the movement of the laser head 200 and the activation ofthe laser beam. Pressing the button 574 c labeled “Cycle Stop” will haltor pause the cutting and movement, with the option to re-start thecutting and movement where it was halted. Pressing the button 574 dlabeled “Machine Reset” will place the apparatus 50 in a neutralcondition. Pressing the button 574 e labeled “Next” upon completion ofthe cutting will return to the “SELECT OPERATION SCREEN.”

[0137]FIG. 17D shows a “PIERCE SETUP/OPERATION SCREEN” display whichprovides information regarding the pierce operation of the apparatus 50in which the laser head 200 drills a hole to a desired depth into thesurface of the structure to be processed. A “Pierce Status” fieldprovides information regarding the status of the pierce operation andcorresponding instructions to the user. The starting position of thelaser head 200 along the first-axis position system 130 and thesecond-axis position system 150 are provided in the “System Status”field. A “Pierce Parameters” field provides information regardingvarious parameters associated with the drilling of a hole. The laserparameters can include, but are not limited to, the laser power, thelaser spot size, and the time period for drilling (each of which caninfluence the diameter of the resultant hole which is formed in thestructure), and the LBU program number. The parameters can be changed asdescribed above. The buttons 574 labeled “Auto/Dry Run,” “Cycle Start,”“Cycle Stop,” “Machine Reset,” and “Next” operate as described above.

[0138]FIG. 17E shows a “CUT SETUP/OPERATION SCREEN” display whichprovides information regarding the straight cutting operation of theapparatus 50 in which the laser head 200 makes a straight cut to adesired depth in the surface of the structure to be processed. Thestraight cut is preferably along one of the axes of the apparatus 50. A“Cut Status” field provides information regarding the status of the cutoperation and corresponding instructions to the user. The startingposition of the laser head 200 along the first-axis position system 130and the second-axis position system 150 are provided in the “SystemStatus” field. A “Cut Parameters” field provides information regardingvarious parameters associated with the cutting, including, but notlimited to, the speed of motion of the laser head 200, the length of thecut to be made, and the LBU program number. The parameters can bechanged as described above. The buttons 574 f, 574 g labeled “Long Axis”and “Short Axis” are used to select either the first axis or the secondaxis respectively as the axis of motion of the laser head 200. Thebuttons 574 labeled “Auto/Dry Run,” “Cycle Start,” “Cycle Stop,”“Machine Reset,” and “Next” operate as described above.

[0139]FIG. 17F shows a “SURFACE KEYING SETUP/OPERATION SCREEN” displaywhich provides information regarding the surface keying operation of theapparatus 50 in which the laser head 200 cuts an indentation or key intothe surface of the structure to be processed. The surface keyingoperation includes scanning the laser beam across the surface to createan indentation or “key” in the surface with a desired depth and with agenerally rectangular area. In certain embodiments, the surface keyingoperation can be used to perform “scabbling” of the surface, whereby thesurface is roughened by interaction with the laser beam across an area(e.g., rectangular).

[0140] A “Surface Keying Status” field provides information regardingthe status of the surface keying operation and correspondinginstructions to the user. The starting position of the laser head 200along the first-axis position system 130 and the second-axis positionsystem 150 are provided in the “System Status” field. A “Surface KeyingParameters” field provides information regarding various parametersassociated with the cutting, including, but not limited to, the speed ofmotion of the laser head 200, the length of the key to be made along thefirst axis and along the second axis, the offset length that theapparatus 50 will increment between movement along the first axis andthe second axis, and the LBU program number. The parameters can bechanged as described above. The buttons 574 f, 574 g labeled “Long Axis”and “Short Axis” are used to select either the first axis or the secondaxis respectively as the axis of motion of the laser head 200. Thebuttons 574 labeled “Auto/Dry Run,” “Cycle Start,” “Cycle Stop,”“Machine Reset,” and “Next” operate as described above.

[0141]FIG. 17G shows a “FAULT SCREEN” display which provides informationregarding detected operation faults. A fault occurs when a sensor (e.g.,flowmeters, temperature sensors, safety switches, emergencies stops) ofthe monitored systems detects a non-operational condition, and can occurwhile the apparatus 50 is any of the operational modes and while any ofthe screens are being displayed. When a fault occurs, a scrollingmessage indicating the fault is preferably provided at the bottom of thecurrent screen being displayed. In addition, the “Machine Status” fieldwill indicate to the user to clear the faults. The “FAULT SCREEN” can beaccessed from any of the other screens by pressing an appropriate button574. As illustrated in FIG. 17G, in certain embodiments, the “FAULTSCREEN” displays the detected faults in a table with the relevant data,including, but not limited to, the date and the type of fault. Toprepare the apparatus 50 for operation, the detected faults arepreferably cleared by the user. After clearing the detected faults, theuser can press an appropriate button 574 (e.g., “Acknowledge All”) toacknowledge the faults. If the faults are not cleared, the user canpress an appropriate button 574 (e.g., “Machine Reset”) to return to thescreen being displayed when the fault occurred. Pressing the “MachineReset” button 574 again will return the user to the “MAIN SCREEN” fromwhere the apparatus 50 can be reset.

[0142]FIG. 17H shows a “MAINTENANCE SCREEN” display which providesinformation regarding the apparatus 50. The maintenance mode can beaccessed from the “MAIN SCREEN” display by pressing an appropriatebutton 574. In the maintenance mode, the system interlocks are bypassed,therefore the user preferably practices particular care to avoiddamaging the apparatus 50 or people or materials in proximity to theapparatus 50. The “MAINTENANCE SCREEN” can display an appropriatewarning to the user.

[0143] The maintenance mode provides an opportunity for the user tocheck the operation of various components of the apparatus 50independent of the fault status of the apparatus 50. For example, bypressing appropriate buttons 574 in the maintenance mode, the vacuumsystem can be turned on and off, the compressed air can be turned on andoff via a solenoid valve, and the first drive 136 and second drive 154can be turned on and off. In addition, the default jog speed of thefirst axis and second axis can be changed by pressing the screen 572 topop up a numerical keypad display, as described above.

[0144] The “System Status” field also includes a plurality of statusboxes which indicate the status of various components of the apparatus50, including, but not limited to, the vacuum pads 112 of the anchoringsystem 110, the air or vacuum pressure, the first-axis position system130, and the second-axis position system 150. The “System Status” fieldalso indicates whether there are any faults sensed with the laser baseunit 300. In certain embodiments, nominal status of a component is shownwith the corresponding status box as green. The ready state of theapparatus 50 is illustrated by having all the system status boxes appearas green. If the status of one of these components is outsideoperational parameters, the corresponding status box is shown as red.

[0145] The “MAINTENANCE SCREEN” can also provide the capability to movethe laser head 200 along the first axis and second axis, as desired. Aset of three buttons 574 are configured to move the laser head 200 alongthe first axis to a home position, in a forward direction, or in abackward direction, respectively. Similarly, another set of threebuttons 574 are configured for similar movement of the laser head 200along the second axis. The label field for these sets of buttons caninclude information regarding the position of the laser head 200 alongthese two axes.

[0146] Detector

[0147] In certain embodiments, the controller 500 is coupled to adetector 600 adapted to detect embedded material in the structure whileprocessing the structure, and to transmit detection signals to thecontroller 500. In certain embodiments, the controller 500 is adapted toavoid substantially damaging the embedded material by transmittingappropriate control signals to the laser base unit 300 and the lasermanipulation system 100. In certain embodiments, the detector 600 isadapted to utilize light emitted by the interaction region duringprocessing to detect embedded material.

[0148] Various technologies for detecting embedded material arecompatible with embodiments of the present invention. Spectral analysisof the light emitted by the interaction region during processing canprovide information regarding the chemical constituents of the materialin the interaction region. By analyzing the wavelength and intensity ofthe light, it is possible to determine the composition of the materialbeing heated and its temperature. Using spectroscopic information, thedetection of embedded materials in certain embodiments relies onmonitoring changes in the light spectrum during processing. With thedifferences in composition of embedded materials, by way of example andnot limitation, such as rebar (e.g., steel) embedded in concrete,variations in the melting and boiling temperatures for the diversematerials will produce noticeable changes in the amount of light, and/orthe wavelength of the light when the laser light impinges and heats theembedded material.

[0149]FIG. 18 schematically illustrates a detector 600 compatible withembodiments described herein. The detector 600 comprises a focusing lens610, an optical fiber 620, and a spectrometer 630. The spectrometer 630of certain embodiments comprises an optical grating 632 and a lightsensor 634. In certain embodiments, the spectrometer 630 also comprisesa microprocessor to analyze the resulting spectroscopic data. In otherembodiments, the spectrometer 630 is coupled to such a microprocessor.The focusing lens 610 is positioned to receive light emitted from theinteraction region, which is directed onto the optical fiber 620. Theoptical fiber 620 then delivers the light to the spectrometer 630, andthe optical grating 632 of the spectrometer 630 separates the light intoa spectrum of wavelengths. The separated light having a selected rangeof wavelengths can then be directed onto the light sensor 634 whichgenerates a signal corresponding to the intensity of the light in therange of wavelengths. The spectrometer 630 can monitor specificwavelengths that are associated with various embedded materials in thestructure. In certain embodiments, the spectrometer 630 can monitor therelative intensity of the light at, or in spectral regions in proximityto, these wavelengths. Additionally, at least one neutral density filtermay be employed to decrease the light reaching the spectrometer 630 toimprove spectral analysis performance.

[0150] In certain embodiments, at least a portion of the detector 600 ismounted onto the laser head 200. In embodiments in which the focusinglens 610 is part of the laser head 200, the focusing lens 610 can bepositioned close to the axis of the emitted laser light so as to receivelight from the interaction region. In such embodiments, the focusinglens 610 can be behind the nozzle 244 and protected by the compressedair from the compressed air inlet 249, as is the window 243. In certainembodiments, the focusing lens 610 is coaxial with the laser beam, whilein other embodiments, the focusing lens 610 is located off-axis.

[0151] Exemplary focusing lenses 610 include, but are not limited to,UV-74 from Ocean Optics of Dunedin, Fla. Exemplary optical fibers 620include, but are not limited to, P400-2-UV/VIS from Ocean Optics ofDunedin, Fla. Exemplary spectrometers 630 include, but are not limitedto, USB2000(VIS/UV) from Ocean Optics of Dunedin, Fla.

[0152] In certain embodiments, the spectrometer 630 monitors theintensity at a specific wavelength and the intensities on both sides ofthis wavelength. The spectrometer 630 of certain embodiments alsomonitors the reduction of the intensities resulting from the increaseddepth of the hole being drilled. FIG. 19 shows an exemplary graph of thelight spectrum detected upon irradiating concrete with laser light andthe light spectrum detected upon irradiating an embedded rebar. Thespectrum from concrete shows an emission peak at a wavelength ofapproximately 592 nanometers. The spectrum from rebar does not have thisemission peak, but instead shows an absorption dip at approximately thesame wavelength. Thus, the emission spectrum at about 592 nanometers canbe used to provide a real-time indication of whether an embedded rebaris being cut by the laser light. For example, by sampling the emissionspectrum at about 588.5 nanometers, 592 nanometers, and 593 nanometers,and calculating the ratio: (2×I₅₉₂)/(I₅₉₃+I_(588.5)), the detector 600can determine whether the emission spectrum has a dip corresponding toconcrete or a peak corresponding to embedded rebar. Other spectroscopicdata can be used in other embodiments.

[0153] An alternative technology for detecting embedded materials useshigh speed shutter monitoring. This approach utilizes advances inCoupled Capacitance Discharge (CCD) camera systems to monitor discretechanges in the interactions between the material to be processed and thelaser light. Newer CCD cameras have systems that can decrease the timethe shutter is open to about 0.0001 second. At this speed, it ispossible to see many features of the interaction between the laser lightand the material being processed. Additionally, neutral density filtersmay be employed to decrease the glare observed from the incandescentinteraction of the laser light and the material to be processed and tobetter image the interaction region.

[0154] Numerous alterations, modifications, and variations of thevarious embodiments disclosed herein will be apparent to those skilledin the art and they are all anticipated and contemplated to be withinthe spirit and scope of the instant invention. For example, althoughspecific embodiments have been described in detail, those with skill inthe art will understand that the preceding embodiments and variationscan be modified to incorporate various types of substitute and/oradditional or alternative materials, relative arrangement of elements,and dimensional configurations. Accordingly, even though only fewvariations of the present invention are described herein, it is to beunderstood that the practice of such additional modifications andvariations and the equivalents thereof, are within the spirit and scopeof the invention as defined in the following claims.

[0155] The corresponding structures, materials, acts, and equivalents ofall means or step plus function elements in the claims below areintended to include any structure, material, or acts for performing thefunctions in combination with other claimed elements as specificallyclaimed.

What is claimed is:
 1. A detection system for use during irradiation ofan interaction region of a structure with laser light, the structurecomprising embedded material, the detection system comprising: afocusing lens positioned to receive light emitted from the interactionregion; an optical fiber optically coupled to the focusing lens toreceive light from the focusing lens; and a spectrometer opticallycoupled to the optical fiber to receive light from the optical fiber,the spectrometer adapted for analysis of the light for indications ofthe embedded material within the interaction region.
 2. The detectionsystem of claim 1, wherein the structure comprises concrete and theembedded material comprises rebar.
 3. The detection system of claim 1,wherein the spectrometer comprises: an optical grating adapted toseparate the light into a spectrum of wavelengths; and a light sensoroptically coupled to the optical grating, the light sensor adapted toreceive light in at least a portion of the spectrum and to generate asignal corresponding to an intensity of the received light.
 4. Thedetection system of claim 3, wherein the light sensor comprises acoupled-capacitance discharge camera system.
 5. The detection system ofclaim 1, further comprising at least one neutral density filter adaptedto reduce the light received by the spectrometer.
 6. The detectionsystem of claim 1, wherein the focusing lens is coaxial with the laserlight impinging on the interaction region.
 7. The detection system ofclaim 1, wherein the focusing lens is off-axis with the laser lightimpinging on the interaction region.
 8. The detection system of claim 1,wherein the structure comprises concrete and the embedded materialcomprises rebar, and the spectrometer is adapted to analyze light havingwavelengths of approximately 592 nanometers for indications of rebarwithin the interaction region.
 9. The detection system of claim 8,wherein the spectrometer is further adapted to analyze light havingwavelengths of approximately 588.5 nanometers and approximately 593nanometers by calculating a ratio of twice the intensity of light at 592nanometers divided by the sum of the intensities at 588.5 nanometers andat 593 nanometers.
 10. The detection system of claim 9, wherein theratio being greater than or equal to one corresponds to rebar within theinteraction region.
 11. A detection system for use during irradiation ofan interaction region of a structure with laser light, the structurecomprising embedded material, the detection system comprising: means forfocusing light emitted from the interaction region; means for separatingthe focussed light into a spectrum of wavelengths; and means foranalyzing at least a portion of the spectrum for indications of embeddedmaterial within the interaction region.
 12. A method of detecting rebarwithin a laser-irradiated interaction region of a structure comprisingembedded material, the method comprising: focussing light from theinteraction region; separating the light into a spectrum of wavelengths;and analyzing at least a portion of the spectrum for indications ofembedded material within the interaction region.